Bitcoin news 2017
Publish: 2021-04-19 06:25:35
1. It's hard to judge by bitcoin. Because although e-money is very convenient and hidden, it lacks normative transaction and has great risk, so it has been stopped in China. Shanlin financial experts said that in the long run, unless there is a legal plan for e-money, there is still a long way to go for the currency to be "electronic".
2. Official and legal platforms have been closed, and recharge has been suspended. They can download but can't trade. There are still a lot of platforms and swindler apps that are transferred overseas,
3. Bitcoin, in short, is an internationally recognized virtual currency. In some foreign countries, bitcoin can be used to trade; In China, it was also announced a while ago that bitcoin withdrawal might be tried out
bitcoin will be released on the Internet regularly to mine. To put it bluntly, it is the process that people use computer hardware to calculate the location of bitcoin and obtain it
mining is definitely the first professional mining machine. Many new children's shoes will choose to mine with graphics card. However, mining with graphics card is just like doing a professional job with "magic oil", but the efficiency is certainly not high. To dig bitcoin, we should pay attention to the following points: first, computing power (i.e. mining speed), second, power consumption, and third, stable performance. Computing power, bitcoin mining is faster than problem-solving speed, so it is self-evident that speed is more important; Power consumption is directly related to efficiency, that is, the issue of cost expenditure; The stability of performance mainly depends on the stability of calculation force when the working frequency is constant. Just think about it, no one wants the miner to lose its computing power every so often, or even break down. After all, it's all money ~
the general computing power of the graphics card is a few gigabytes, while the professional miner chip is as high as several thousand gigabytes. Take bm1387, the chip with the lowest power consumption in the world, as an example, the S9's computing power is as high as 14T, the power consumption on the wall is only 1400W, and the rated computing power reaches 13.5 Th / s ± 1 J / GH + 12% (wall, AC / DC 93% efficiency, 25 ° Rated voltage: 11.6 ~ 13.0v, in addition, in the case of non independent power supply, three power calculation boards can be connected to different power supply respectively, but each power calculation board can not be connected to multiple power supply, and ensure that the power calculation board is finally powered on
among the mining machines, ant mining machine is my favorite. At the same time, based on the average investment cost of bitcoin in the early stage, ant S9 can basically recover the capital in about five months, and the income in the later stage is immeasurable.
bitcoin will be released on the Internet regularly to mine. To put it bluntly, it is the process that people use computer hardware to calculate the location of bitcoin and obtain it
mining is definitely the first professional mining machine. Many new children's shoes will choose to mine with graphics card. However, mining with graphics card is just like doing a professional job with "magic oil", but the efficiency is certainly not high. To dig bitcoin, we should pay attention to the following points: first, computing power (i.e. mining speed), second, power consumption, and third, stable performance. Computing power, bitcoin mining is faster than problem-solving speed, so it is self-evident that speed is more important; Power consumption is directly related to efficiency, that is, the issue of cost expenditure; The stability of performance mainly depends on the stability of calculation force when the working frequency is constant. Just think about it, no one wants the miner to lose its computing power every so often, or even break down. After all, it's all money ~
the general computing power of the graphics card is a few gigabytes, while the professional miner chip is as high as several thousand gigabytes. Take bm1387, the chip with the lowest power consumption in the world, as an example, the S9's computing power is as high as 14T, the power consumption on the wall is only 1400W, and the rated computing power reaches 13.5 Th / s ± 1 J / GH + 12% (wall, AC / DC 93% efficiency, 25 ° Rated voltage: 11.6 ~ 13.0v, in addition, in the case of non independent power supply, three power calculation boards can be connected to different power supply respectively, but each power calculation board can not be connected to multiple power supply, and ensure that the power calculation board is finally powered on
among the mining machines, ant mining machine is my favorite. At the same time, based on the average investment cost of bitcoin in the early stage, ant S9 can basically recover the capital in about five months, and the income in the later stage is immeasurable.
4.
Yes , January 22 , the price of bitcoin continued to decline in the previous two days. According to the price of coindesk, the bitcoin price once fell to $28845 , 17.83% lower than the highest price of $35102 in 24 hours
as of 10:10, the price of bitcoin was about US $29918, with a decrease of 13.94% in 24 hours. The turnover of bitcoin in 24 hours was US $70.71 billion, with a market value of US $556.66 billion. This is the third consecutive day that the price of bitcoin has fallen. On January 20, the price of bitcoin fell from more than $37000 to less than $35000, and then fell below $32000 on January 21
extended data
the dispute over the price of bitcoin continues:
in the past seven days, bitcoin has experienced a roller coaster like correction, falling for three consecutive days and piercing the 10 day moving average downward. Compared with the historical high of nearly 42000 US dollars in the first ten days of this month, it has dropped to more than 10000 US dollars in just a few days
at present, the dispute over the price of bitcoin continues: those who believe that bitcoin will continue to rise believe that institutions' understanding of the digital currency is graally maturing and use it as a hedge against inflation; Opponents argue that this is just another bubble after the collapse of the bitcoin in 2017. p>
John Normand and Federico manicaldi, strategists of JPMorgan Chase, wrote in a report on Thursday that bitcoin has set the fastest price appreciation record in the history of major assets, and the current price is far higher than its mining cost, which means that the decline of bitcoin's return rate will be inevitable
5. Personal use of mining machinery, but also consider the site fees, maintenance fees, residential electricity. The small ones can't afford the electricity bill. The large-scale ones can afford to pay for electricity.
6. Manual shooting skills of SLR camera
1. Take close-up pictures of small still objects, such as flowers, birds and insects:
use AV file, the aperture should be f5.6 or below, the focal length should be more than 50, and try to shoot within 1m to make the background virtual
if the light is good, ISO 100, if the light is bad, ISO should be within 400<
2. Shooting people:
basically use a large aperture (within f5.6) and a focal length of more than 50 mm. The shooting distance depends on the whole body, half body and big head, which makes the background virtual. Use AV file
good light, iso100, bad light, iso400
people in motion use tracking to reflect the sense of motion (see the shooting of moving objects below for details)<
3. Shooting:
AV file, use the appropriate aperture, above F8, the focal length is arbitrary, but generally the wide-angle end has distortion, use it as appropriate<
4. Shooting night scene:
upper tripod, AV gear, custom white balance or incandescent lamp, aperture above F8, small aperture can make the light proce starlight effect, use the reflector pre rising function to rece the vibration caused by the reflector lifting after pressing the shutter; And cover the viewfinder with the square cover on the strap to prevent stray light from entering from the back and affecting the image quality; ISO 200, as far as possible to make the exposure time longer, so that some people who have no intention to walk away from the screen disappear, leaving no traces, clean the scene
for example, when taking a square with people coming and going, you can use a very small aperture of about F20 and iso100. In this way, the exposure time will be very long, and the moving figures will not stay in the photos! The square will be clean<
5. Shooting fireworks:
using shutter line and B shutter, you can shoot multiple fireworks overlapping effect<
6. Shooting things:
when the light is good: AV, the aperture size should be handled according to the circumstances; Large depth of field can be obtained by using aperture above F8, and shallow depth of field can be obtained by using small aperture
if you want to have a very dynamic effect, you can use the TV gear, the shutter is about 1 / 30, when you focus and press the shutter, the lens will follow the object at an appropriate speed, which will proce a very dynamic effect
poor lighting: we can only handle it according to our own discretion, plus use the follow-up camera<
7. Shooting running water or fountain:
using TV and about 1 / 50 shutter speed, you can shoot Satin effect. If you use too fast shutter speed, the fountain will shoot discontinuous water drops<
8. Taking photos at night:
use tripod to adjust white balance, and automatically or custom white balance; iso100-400 AV gear, aperture about F8, use slow synchronous flash, rear curtain flash mode; At this time, the flash will flash twice, press the shutter to flash once, and flash again before the end of exposure, so don't leave before flashing twice
in this way, the characters can be clear and the background neon is beautiful, so that the background will not be too dark e to insufficient exposure< No matter what you shoot, don't shoot with the maximum aperture unless you want to keep a safe shutter
2. Please use the aperture of F8 ~ F11 as much as possible when shooting scenery
3. The maximum aperture can be reced by 1-2 levels when taking close-up of people and still life
4. The safety shutter should be controlled above the reciprocal of the focal length as far as possible. The wide-angle shutter should also be more secure at more than 1 / 30 second. If the shutter is insufficient, please increase the aperture or ISO<
metering method:
1. Don't measure the light to the sky or the darkest place. Go to the middle value
2. According to your subject matter, make good use of the metering mode (balance metering, point metering, central key metering...)
3. If the light measurement is not accurate, please use AE lock to expose and lock the gray things around you before shooting
4. Try not to measure the light on white or black objects, otherwise remember to rece eV for black and increase eV for white<
EV is exposure compensation.
exposure compensation is also an exposure control method, which is commonly used in ± If the ambient light source is dim, the exposure value (such as + 1eV, + 2eV) can be increased to highlight the clarity of the picture
most of the small digital cameras adjust the exposure compensation through the menu
in the process of shooting, if you press half of the shutter, the LCD will display pictures similar to the final effect picture, focusing and exposure will start. The exposure at this time is exactly the exposure of the final picture. If the picture is obviously bright or dark, it means that the automatic metering accuracy of the camera has a large deviation, and the exposure compensation should be enforced, but sometimes the brightness displayed ring shooting is different from the actual shooting result. Digital camera can browse the picture immediately after shooting, at this time, you can more accurately see the brightness of the picture, there will be no difference. If the shooting result is obviously bright or dark, it is necessary to re shoot and force the exposure compensation
the shooting environment is dim, and the brightness needs to be increased. When the flash cannot work, the exposure can be compensated and the exposure can be increased appropriately. For exposure compensation, if the photo is too dark, increase the EV value. Every 1.0 increase in EV value is equivalent to doubling the amount of light intake. If the photo is too bright, decrease the EV value. Every 1.0 decrease in EV value is equivalent to doubling the amount of light intake. The compensation interval can be adjusted in 1 / 2 (0.5) or 1 / 3 (0.3) units according to different cameras
when the white object to be photographed looks gray or not white enough in the photo, it is necessary to increase the exposure. In short, "the whiter the object is, the more white the object is." this seems to run counter to the basic principles and habits of exposure. In fact, it is not. This is because the main body of the camera is often the center of the light measurement, and the White main body will make the camera mistakenly think that the environment is very bright, As a result, the exposure is insufficient, which is also a common problem for most beginners
because the shutter time or aperture size of the camera is limited, it is not always able to reach the 2eV adjustment range, so the exposure compensation is not omnipotent, and it may still be underexposed in too dark environment. At this time, it is necessary to consider cooperating with the flash or increasing the ISO sensitivity of the camera to improve the brightness of the picture
generally speaking, the smaller the brightness contrast of the scene, the more accurate the exposure, otherwise, the larger the deviation. The grade of the camera is high and low. If the grade is high, the metering is more accurate, and if the grade is low, the deviation will be increased. If it is a traditional camera, the tolerance of film is relatively large, and the exposure deviation will not have a big problem within a certain range, but the CCD tolerance of digital camera is relatively small, and slight exposure deviation may affect the overall effect
in a word, the adjustment of exposure compensation is determined by experience and sensitivity to color. Users must compare the image quality, clarity, restoration degree and noise size under different exposure compensation to get the best picture
note:
the aperture in Canon's manual refers to the F value. The larger the aperture, the greater the depth of field
generally speaking, aperture refers to aperture, which is inversely proportional to F. the larger the aperture, the smaller the depth of field
AV -- aperture priority auto exposure
TV -- shutter priority auto exposure
AE auto exposure
AF auto focus
AF-S -- single auto focus, the same as saf. The opposite is continuous autofocus
MAF - monitor AF, which can shorten the focusing time. The camera will adjust the focus before half pressing the shutter button, so that you can compose with the adjusted focus. When the shutter button is half pressed and AF locking is completed, the focus will be locked
ev - exposure value, which is usually used in exposure compensation
ISO sensitivity. Each difference of sensitivity is equivalent to the corresponding exposure value of aperture or shutter
brother, if you have time, go to ZhongGuanCun video forum and see the forum.
1. Take close-up pictures of small still objects, such as flowers, birds and insects:
use AV file, the aperture should be f5.6 or below, the focal length should be more than 50, and try to shoot within 1m to make the background virtual
if the light is good, ISO 100, if the light is bad, ISO should be within 400<
2. Shooting people:
basically use a large aperture (within f5.6) and a focal length of more than 50 mm. The shooting distance depends on the whole body, half body and big head, which makes the background virtual. Use AV file
good light, iso100, bad light, iso400
people in motion use tracking to reflect the sense of motion (see the shooting of moving objects below for details)<
3. Shooting:
AV file, use the appropriate aperture, above F8, the focal length is arbitrary, but generally the wide-angle end has distortion, use it as appropriate<
4. Shooting night scene:
upper tripod, AV gear, custom white balance or incandescent lamp, aperture above F8, small aperture can make the light proce starlight effect, use the reflector pre rising function to rece the vibration caused by the reflector lifting after pressing the shutter; And cover the viewfinder with the square cover on the strap to prevent stray light from entering from the back and affecting the image quality; ISO 200, as far as possible to make the exposure time longer, so that some people who have no intention to walk away from the screen disappear, leaving no traces, clean the scene
for example, when taking a square with people coming and going, you can use a very small aperture of about F20 and iso100. In this way, the exposure time will be very long, and the moving figures will not stay in the photos! The square will be clean<
5. Shooting fireworks:
using shutter line and B shutter, you can shoot multiple fireworks overlapping effect<
6. Shooting things:
when the light is good: AV, the aperture size should be handled according to the circumstances; Large depth of field can be obtained by using aperture above F8, and shallow depth of field can be obtained by using small aperture
if you want to have a very dynamic effect, you can use the TV gear, the shutter is about 1 / 30, when you focus and press the shutter, the lens will follow the object at an appropriate speed, which will proce a very dynamic effect
poor lighting: we can only handle it according to our own discretion, plus use the follow-up camera<
7. Shooting running water or fountain:
using TV and about 1 / 50 shutter speed, you can shoot Satin effect. If you use too fast shutter speed, the fountain will shoot discontinuous water drops<
8. Taking photos at night:
use tripod to adjust white balance, and automatically or custom white balance; iso100-400 AV gear, aperture about F8, use slow synchronous flash, rear curtain flash mode; At this time, the flash will flash twice, press the shutter to flash once, and flash again before the end of exposure, so don't leave before flashing twice
in this way, the characters can be clear and the background neon is beautiful, so that the background will not be too dark e to insufficient exposure< No matter what you shoot, don't shoot with the maximum aperture unless you want to keep a safe shutter
2. Please use the aperture of F8 ~ F11 as much as possible when shooting scenery
3. The maximum aperture can be reced by 1-2 levels when taking close-up of people and still life
4. The safety shutter should be controlled above the reciprocal of the focal length as far as possible. The wide-angle shutter should also be more secure at more than 1 / 30 second. If the shutter is insufficient, please increase the aperture or ISO<
metering method:
1. Don't measure the light to the sky or the darkest place. Go to the middle value
2. According to your subject matter, make good use of the metering mode (balance metering, point metering, central key metering...)
3. If the light measurement is not accurate, please use AE lock to expose and lock the gray things around you before shooting
4. Try not to measure the light on white or black objects, otherwise remember to rece eV for black and increase eV for white<
EV is exposure compensation.
exposure compensation is also an exposure control method, which is commonly used in ± If the ambient light source is dim, the exposure value (such as + 1eV, + 2eV) can be increased to highlight the clarity of the picture
most of the small digital cameras adjust the exposure compensation through the menu
in the process of shooting, if you press half of the shutter, the LCD will display pictures similar to the final effect picture, focusing and exposure will start. The exposure at this time is exactly the exposure of the final picture. If the picture is obviously bright or dark, it means that the automatic metering accuracy of the camera has a large deviation, and the exposure compensation should be enforced, but sometimes the brightness displayed ring shooting is different from the actual shooting result. Digital camera can browse the picture immediately after shooting, at this time, you can more accurately see the brightness of the picture, there will be no difference. If the shooting result is obviously bright or dark, it is necessary to re shoot and force the exposure compensation
the shooting environment is dim, and the brightness needs to be increased. When the flash cannot work, the exposure can be compensated and the exposure can be increased appropriately. For exposure compensation, if the photo is too dark, increase the EV value. Every 1.0 increase in EV value is equivalent to doubling the amount of light intake. If the photo is too bright, decrease the EV value. Every 1.0 decrease in EV value is equivalent to doubling the amount of light intake. The compensation interval can be adjusted in 1 / 2 (0.5) or 1 / 3 (0.3) units according to different cameras
when the white object to be photographed looks gray or not white enough in the photo, it is necessary to increase the exposure. In short, "the whiter the object is, the more white the object is." this seems to run counter to the basic principles and habits of exposure. In fact, it is not. This is because the main body of the camera is often the center of the light measurement, and the White main body will make the camera mistakenly think that the environment is very bright, As a result, the exposure is insufficient, which is also a common problem for most beginners
because the shutter time or aperture size of the camera is limited, it is not always able to reach the 2eV adjustment range, so the exposure compensation is not omnipotent, and it may still be underexposed in too dark environment. At this time, it is necessary to consider cooperating with the flash or increasing the ISO sensitivity of the camera to improve the brightness of the picture
generally speaking, the smaller the brightness contrast of the scene, the more accurate the exposure, otherwise, the larger the deviation. The grade of the camera is high and low. If the grade is high, the metering is more accurate, and if the grade is low, the deviation will be increased. If it is a traditional camera, the tolerance of film is relatively large, and the exposure deviation will not have a big problem within a certain range, but the CCD tolerance of digital camera is relatively small, and slight exposure deviation may affect the overall effect
in a word, the adjustment of exposure compensation is determined by experience and sensitivity to color. Users must compare the image quality, clarity, restoration degree and noise size under different exposure compensation to get the best picture
note:
the aperture in Canon's manual refers to the F value. The larger the aperture, the greater the depth of field
generally speaking, aperture refers to aperture, which is inversely proportional to F. the larger the aperture, the smaller the depth of field
AV -- aperture priority auto exposure
TV -- shutter priority auto exposure
AE auto exposure
AF auto focus
AF-S -- single auto focus, the same as saf. The opposite is continuous autofocus
MAF - monitor AF, which can shorten the focusing time. The camera will adjust the focus before half pressing the shutter button, so that you can compose with the adjusted focus. When the shutter button is half pressed and AF locking is completed, the focus will be locked
ev - exposure value, which is usually used in exposure compensation
ISO sensitivity. Each difference of sensitivity is equivalent to the corresponding exposure value of aperture or shutter
brother, if you have time, go to ZhongGuanCun video forum and see the forum.
7. Video memory can be shared with memory. For example, 4G video memory can be shared with 8g memory ~
I hope it will help you
I hope it will help you
8. Andre, a security researcher at the University of Washington; Dimino noticed that several IP addresses were trying to hijack a Linux server by using a fixed PHP vulnerability. He was curious about how the attacker successfully controlled a Linux server, so he set up a honeypot to run an old version of PHP and let the attacker hijack and observe. Dimino found that the attacker was very cunning indeed. He sent out an HTTP post request containing multiple instructions, downloaded a Perl script disguised as a PDF file, executed it and then deleted it
to ensure success, the attacker uses curl, fetch and LWP get requests to repeat the above steps. Perl script programming sleep for a period of time, guess may be to avoid the administrator's ears and eyes. Finally, the infected machine connects to a relay chat channel to download and execute another script. The attacker installed several applications on the server, including bitcoin and prime coin mining programs, DDoS tools, and tools for scanning other machines with known vulnerabilities. With the popularity of Linux server, it has become an attractive target in the eyes of attackers just like windows PC.
to ensure success, the attacker uses curl, fetch and LWP get requests to repeat the above steps. Perl script programming sleep for a period of time, guess may be to avoid the administrator's ears and eyes. Finally, the infected machine connects to a relay chat channel to download and execute another script. The attacker installed several applications on the server, including bitcoin and prime coin mining programs, DDoS tools, and tools for scanning other machines with known vulnerabilities. With the popularity of Linux server, it has become an attractive target in the eyes of attackers just like windows PC.
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